package com.itheima.domain;

/**
 *
 * @Title :
 * @Description : 被观察者 的接口

 * @param null
 * @return
 *
 * @user : Yrd
 * @date : 2021-11-02 14:33
 */
public interface Subject {
    //methods to register and unregister observers
    public void register(Observer observer);
    public void unregister(Observer observer);

    //method to notify observers of change
    public void notifyObservers();

    //method to get updates from subject
    public Object getUpdate(Observer observer);
}
